1. Field
The present invention relates generally to orthotic medical devices. More specifically, embodiments of the present invention concern an ankle stabilizer that supports an ankle joint by restricting inversion and/or eversion of the foot while permitting plantar flexion and/or dorsiflexion of the foot.
2. Discussion of Prior Art
The ankle comprises a synovial joint and connects the foot to the tibia and fibula of the leg. The ankle and foot include numerous bones that are interconnected by ligaments, muscles, and other tissues. These ligaments are prone to various types of high and low ankle sprains caused by excessive foot movement, such as eversion (when the foot is turned outwardly relative to the leg and causes undue stretching of medial ligaments) or inversion (when the foot is turned inwardly relative to the leg and causes undue stretching of lateral ligaments) of the ankle.
Various conventional devices have been employed to support or immobilize the ankle joint and thereby provide orthotic treatment of sprains. For example, a splint-type brace is particularly used for immobilizing the ankle joint during the acute stage of ankle injury. However, this type of brace is typically bulky and therefore cannot be worn inside a shoe or clothing. Another serious problem with a “splint-type” brace is that essentially all joint function is prevented, which restricts activity involving use of the joint and can thereby slow rehabilitation and promote muscle atrophy.
Wrapping of the joint with a cloth bandage or tape is another conventional technique for immobilizing a joint. Although cloth or tape wraps are more comfortable and less bulky than “splint-type” braces, the wraps likewise immobilize the joint and therefore present the same problems of atrophy, lack of performance during the rehabilitation stage of the injury, and excessive restriction of joint function. Cloth and tape wraps are particularly problematic because they encircle the joint and adjacent body parts, such as the top of the foot, and also preclude necessary dorsi and plantar flexion of the ankle joint.
Braces have been designed for use during the rehabilitation stage of injuries. Rehabilitative braces typically include a pliable sleeve formed of elastic material for placement on the joint and adjacent body parts. For example, a rehabilitative ankle brace traditionally comprises a boot-shaped sleeve that is tightened about the lower leg, ankle joint and foot by suitable lacing. Although this type of brace is comfortable and capable of being worn within a shoe, the sleeve itself provides little support to the joint. Accordingly, the sleeve would not be effective during the acute stage of an injury because of its failure to sufficiently restrict movement of the joint. Even when the sleeve is used for rehabilitative purposes, it restricts movement of the joint in virtually any direction and, consequently, fails to permit dorsiflexion and plantar flexion of the foot. It will be appreciated that rehabilitative sleeves are also often used as a prophylaxis for reducing the risk of re-injury.
Rehabilitative sleeves have been provided with various structure in an attempt to broaden their application to include treatment during the acute stage of the injury. For example, sleeves have been provided with rigid splints inserted into pockets formed along the sleeve. However, this type of brace still presents the same problems noted above.
Accordingly, there is a need in the art for improved orthotic devices that treat ankle sprains or serve as a prophylaxis by restricting lateral and medial movement of the foot while permitting dorsiflexion and plantar flexion.